The crystal structures of three 3-methyl-1H-1,2,4triazole-5-thiones, including a second polymorph of 4-(E)-(5-bromo-2-hydroxybenzylidene)amino]-3methyl-1H-1,2,4-triazole- 5(4H)-thione and a redetermination of 4-amino-3-methyl-1H-1,2,4-triazole-5(4H)-thione

Manjula, P. S. and Sarojini, B. K. and Yathirajan, H. S. and Akkurt, M. and Ersanli, C. C. and Glidewell, Christopher (2015) The crystal structures of three 3-methyl-1H-1,2,4triazole-5-thiones, including a second polymorph of 4-(E)-(5-bromo-2-hydroxybenzylidene)amino]-3methyl-1H-1,2,4-triazole- 5(4H)-thione and a redetermination of 4-amino-3-methyl-1H-1,2,4-triazole-5(4H)-thione. Acta Crystallographica Section E-Crystallographic Communications, 71 (9). 1003+. ISSN 2056-9890

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Abstract

The structures of three 3-methyl-1H-1,2,4-triazole-5-thione derivatives are reported. The structure of 4-amino-3-methyl-1H-1,2,4-triazole-5(4H)-thione, C3H6N4S, (I), has been redetermined with an improved model for the H atoms: the non-H atoms of (I) all lie on mirror planes in space group Pbcm, and the H atoms of the methyl group are disordered over two sets of reflection-related atomic sites having occupancy 0.5: two independent N-H center dot center dot center dot S hydrogen bonds link the molecules of compound (I) into complex sheets. The non-H atoms in the molecules of 4-(E)-(3,4-dimethoxybenzylidene) amino]-3-methyl-1H-1,2,4-triazole- 5(4H)-thione, C12H14N4O2S, (II), despite lying in general positions are close to planar, with a dihedral angle between the two rings of 6.31 (10) degrees : the molecules of compound (II) are linked by a three-centre N-H center dot center dot center dot (O)2 hydrogen bond into a C(10) C(11) R12 (5)] chain of rings. A second polymorph of 4-(E)-(5bromo- 2-hydroxy-5-bromobenzylidene) amino]-3-methyl-1H-1,2,4-triazole-5(4H)thione, C10H9BrN4OS, (III), has been identified; the non-H atoms are nearly coplanar with a dihedral angle between the two rings of 1.9 (4) degrees. There is an intramolecular O-H center dot center dot center dot N hydrogen bond and the molecules are linked by NH center dot center dot center dot S hydrogen bonds, forming centrosymmetric R-2(2) (8) dimers. Comparisons are made with some related structures.

Item Type:	Article
Uncontrolled Keywords:	crystal structures; 1H-1,2,4-triazole-5-thiones; polymorphism; hydrogen bonding
Subjects:	C Chemical Science > Chemistry
Divisions:	Department of > Chemistry
Depositing User:	Users 19 not found.
Date Deposited:	30 May 2019 11:21
Last Modified:	03 Aug 2022 10:54
URI:	http://eprints.uni-mysore.ac.in/id/eprint/705

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